In conventional load carrying vehicles, such as enclosed vans, or the like, an elongate freight compartment is generally formed, with access provided through one or more rearly situated doors and/or through intermediate doors in the vehicle sidewalls. In either construction, it is preferable to arrange the internal load such that the cargo to be first unloaded is situated close to the access opening. Load balancing, however, may dictate an arrangement of cargo that is inconvenient from this standpoint. When the cargo to be unloaded is remote from the opening, for whatever reason, it may be necessary to rearrange the entire load to gain access to the desired cargo.
Typically, heavier cargo is introduced to the van by employing a forklift, which has numerous drawbacks. Most notable of these problems is the fact that the additional height of the lifting bars reduces the size of the cargo that can be fit within the compartment. Further, the use of a forklift is undesirable in that the forklift itself is generally extremely heavy and, during the transfer of the cargo, places an undesirable burden on the van.
To obviate this problem, overhead loading can be accomplished as taught in U.S. Pat. No. 715,384, to H. A. Johnston and U.S. Pat. No. 3,106,900, to J. R. Gallo et al. In each, the roof assembly is removable as a unit. The main drawback with this construction is that the roof assembly may be excessive in weight and is not manipulable by an individual without mechanical assistance. Further, even though access may be desired to only one portion of the compartment, the entire roof has to be removed.
As an alternative to this design, a plurality of interconnecting rigid panels are shown in U.S. Pat. No. 3,951,447 to Sharp. In Sharp, the edges of the panels have an integrally formed flange which cooperates with a flange on the next adjacent panel. The panels are removable by means of a cable connecting a lifting bracket, which bracket serves also to lock the panels in place. To gain access to the compartments, the panels must be removed by an external apparatus capable of drawing the cable. A further drawback with this construction is that the panels must be removed successively due to the interconnection of the flanges. Should access be desired to the rear of the vehicle, all the panels would have to be removed, leaving the sidewalls without any lateral stability between the endwalls of the van.
An additional problem that may be encountered in overhead loading is that of introducing loads that are of a length substantially equal to that of the van. Lateral bracing at the roof, adajcent to the endwalls, may restrict the opening and thus reduce the permissible length of the cargo that can be loaded or unloaded from overhead. The bracing might alternately necessitate tipping of the load, which is an awkward process. Even with the entire roof assembly removed, as in Johnston and Gallo et al, one must be careful in introducing or removing loads approximating the length of the van not to damage the endwalls.
The present invention is directed specifically to overcoming one or more of the problems enumerated above.